Convertible spine book



FIG. 1 is a perspective view of a convertible spine book, showing my new design in a first state;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a second perspective view of the convertible spine book in a second state;

FIG. 8 is a front elevational view thereof;

FIG. 9 is a rear elevational view thereof;

FIG. 10 is a right side elevational view thereof;

FIG. 11 is a left side elevational view thereof;

FIG. 12 is a top view thereof; and,

FIG. 13 is a plan view of the design in a pre-folded state.

The broken lines are directed to environment and form no part of the claimed design. 

CLAIM The ornamental design for a convertible book spine, as shown and described. 